The PI has described insulin resistance (IR) in cystic fibrosis (CF) patients, but the cause is unknown. The hypotheses are (1) that IR in CF is caused from post-insulin receptor defects in glucose transporter translocation (GLUT4), and (2) that IR will be correlated with high levels of acute phase reactants such as TNF-alpha. In CF patients and controls, the PI will measure GLUT4 translocation from vastus lateralis; 24 cortisol, growth hormone and catecholamines; and TNF-alpha, C-reative protein and other acute phase reactants. The investigators found that a) when compared to controls, CF patients have decreased translocation of GLUT4; b) CF patients have higher levels of TNF-alpha. There is no difference between controls and CF patients for cortisol, IL-6 and IL-1.